Camera adapter for optical devices, in particular microscopes

ABSTRACT

A camera adapter for optical devices, in particular microscopes. The present solution includes a camera adapter which enables any video cameras and photographic cameras to connect to an existing image out-coupling system, e.g., the beam splitter of a microscope. The adapter can also be used for stereo microscopes. The camera adapter is arranged between the image out-coupling element and the camera. Its housing has two connection pieces. The microscope-side connection piece has a quick-change device and the camera-side connection piece has a filter thread. The technical solution provides a camera adapter for connecting digital cameras to a microscope. By using intermediate rings, the camera adapter is suitable for different cameras and facilitates exchange of cameras. The camera can be positioned in such a way that the observer can view the object through the eyepiece as well as on the camera monitor without substantially changing his/her sitting position.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority of International Application No.PCT/EP03/07876, filed Jul. 18, 2003, and German Application No. 102 40720.7, filed Sep. 4, 2002, the complete disclosures of which are herebyincorporated by reference.

BACKGROUND OF THE INVENTION

a) Field of the Invention

The present technical solution is directed to a camera adapter whichmakes it possible to connect any video cameras and photographic camerasto an existing image out-coupling system, e.g., the beam splitter of amicroscope. The adapter can also be used for stereo microscopes and inparticular for ophthalmic microscopes.

b) Description of the Related Art

According to the known prior art, lensless cameras are connected to aspecial optical output at the microscope or stereomicroscope by acorresponding coupling in order to document microscopic images. T2,C-mount or various bayonet connections, for example, are usually used ascoupling systems. The image information for this special camera outputis generated by splitting the optical beam path or stereo beam path andis imaged on the corresponding recording medium by imaging optics. Inthe solution described in U.S. Pat. No. 5,652,676, the adapter pertainsto a motor-driven zoom objective and has a ring to which video camerasor photographic camera can be connected by a C mount or bayonetconnection. However, since these cameras are usually specific solutionsexclusively in technical fields, the search for other solutions wasintensified.

Cameras that are arranged at the eyepiece connection piece or at theeyepiece of the optical device represent another possibility for imagegeneration. A solution of this kind is described in EP 0 274 038, inwhich the tube image of a slit lamp or of a microscope is imaged on arecording medium by a special adapter and the camera objective. U.S.Pat. No. 5,053,794 describes an adapter ring which is suitable, forexample, to connect a photographic camera or video camera to theeyepiece of a telescope or microscope. While “normal” mirror reflexcameras can be used in these solutions, it is disadvantageous thatbinocular observation is not possible when the camera is connected.

An adapter for connecting a camera to a phototube of a microscope isdescribed in Utility Model Application DE 200 10 421 U1. The adapter hasa lens system and a retaining clip. The intermediate image generated inthe microscope is infinity-imaged by the lens system and projected ontothe recording medium of the connected camera by the objective of thecamera. The retaining clip is fastened to the phototube of themicroscope and has a fastening screw which engages in the stand threadprovided at the camera and thereby fixes the camera. Since there is nouniform standard for the distance of the stand thread from the opticalaxis or for the arrangement of the stand thread at the camera housing,these dimensions vary quite a lot in different cameras. The describedadapter is accordingly only usable for particular cameras and must beadapted for other cameras.

A video attachment for a microscope without a phototube is described inU.S. Pat. No. 5,568,188. The video attachment is connected to themicroscope by connection elements. The alignment of the video attachmentwith respect to the optical axis of the microscope is carried out bymeans of screws that are provided. The adjusted position of the videoattachment is fixed by means of springs and retaining screws. Theoptical axis of the video attachment encloses an angle with the opticalaxis of the microscope so that the images seen by the two elements arenot the same. Accordingly, it is not possible for the image seen in themicroscope to be recorded at the same time by the video camera. Theadjustments at the microscope must be changed for video documentation.Therefore, it can be ensured only with difficulty that the videorecording is the same as the images of the examined eye that theobserver saw previously. Further, this “double” examination takessubstantially more time and is therefore more stressful for the patient.

U.S. Pat. No. 5,134,515 concerns a photographic attachment and a shutterarrangement for a binocular microscope, particularly an ophthalmicmicroscope. The photographic attachment is arranged in the observationbeam path between the magnification changer and the eyepiece tube. Thisphotographic attachment has a movable mirror which swivels into theobservation beam path when actuated and deflects the latter in directionof the provided phototube and the photo camera connected to it. Whenactuated, the shutter adjustment for the photographic recordings changesat the same time. After a slight delay in time, the shutter release ofthe camera and the provided flash are actuated and a recording of theeye is made. After this, all of the moving parts return to theiroriginal positions either by spring force or gravitational force. Thisfrees the observation beam path again so that it is possible to resumeobservation through the eyepiece. Miniature-format cameras andinstant-image cameras can be used by adding different objective tubes.However, the photographic attachment is not suitable for recording videosequences. Further, it is disadvantageous that no observation ispossible while photographic recordings are being made.

It is the primary object of the present technical solution to develop anadapter for connecting a camera, preferably a digital camera, to amicroscope, particularly an ophthalmic microscope. The adapter isequally suitable for different cameras and allows cameras to beexchanged in a simple manner. The camera can be arranged in such a waythat the observer can see the object through the microscope eyepiece aswell as on the monitor located on the back of the camera housing withouthaving to change sitting positions.

This object is met by a camera adapter for optical devices, such asmicroscopes, having an additional image out-coupling element forphotographic documentation of images. The camera adapter is to bearranged between the image out-coupling element and a camera. The cameraadapter comprises a housing with two connection pieces, amicroscope-side connection piece and a camera-side connection piece. Themicroscope-side connection piece has a quick-change device. Thecamera-side connection piece has a filter thread and eyepiece optics.

The technical solution will be described in the following with referenceto an embodiment example.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 shows the basic construction of the camera adapter according tothe invention;

FIG. 2 shows the camera adapter in section A-A; and

FIG. 3 shows the use of the camera adapter on a microscope.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows the camera adapter for optical devices, particularly anophthalmic microscope 1. An additional image out-coupling element 2,such as a swivel mirror or beam splitter, and a surrounding-fieldilluminator 3 for illuminating the object field when using slitprojectors are required for photographic documentation of images indevices of the type mentioned above. The camera adapter to be arrangedbetween the image out-coupling element 2 and the camera comprises ahousing 4 with two connection pieces 5 and 6. The microscope-sideconnection piece 5 preferably has a quick-change device 9 such as isknown from other microscope accessory units and has tube optics 7. Thecamera adapter is positively centered by this quick-change device 9 sothat the optical axis of the camera coincides with that of themicroscope 1 or of an optical channel of a stereo microscope.

In contrast, the camera-side connection piece 6 has a filter thread 10and has eyepiece optics 8. The filter thread 10 is preferably M37 andcan be adapted to different diameters of filter threads 10 or objectivecylinders by using intermediate rings 12.

Commercially available digital cameras with an objective, filter threadand preferably also with a monitor on the back of the housing are used.The camera-side connection piece 6 is rotatable in the housing 4 so thatthe camera, which is sometimes seated obliquely at the filter thread 10,can be brought into a straight position together with the connectionpiece 6. The connection piece 6 is prevented from turning again by meansof a securing device 11. The camera adapter is advantageouslyconstructed over a combined prism/mirror arrangement so as to allowergonomic viewing of the monitor located at the back of the camera andcustomary operation.

The surrounding-field illuminator 3 which may possibly be required forphotographic documentation comprises a light-emitting diode which emitswhite light in special cases. Its brightness can be regulated by adimmer 13 and can be adapted to different illumination conditions so asto ensure that the slit image will be displayed in an optimal manner ona favorably illuminated surrounding field (eye). Power is supplied bymeans of the power supply of the microscope 1. The surrounding-fieldilluminator 3 can have an attachment plug that fits into an openingprovided at the microscope 1. The surrounding-field illuminator 3 isswitched on when slit recordings are made in darkened rooms and thelocation of the slit image is to be displayed on the eye.

In a particular construction, the LED is based, for example, on ahigh-performance blue LED with a wavelength of 450 nm that excites lightemission in a special layer at around 550 nm. The illumination maximagive a bluish-white, very intensive light. Accordingly, the light sourcecan also be used as an excitation light for fluorescence examinations,i.e., for diagnosing with contrast media or fluorescence media.

A right-angle prism 14 and a mirror 15 are arranged in the housing 4 ofthe camera adapter as additional beam-deflecting elements in such a waythat the optical axes of the connection pieces 5 and 6 enclose an angleof less than 180°. In this connection, FIG. 2 shows the camera adapterin a sectional view. An angle of 120°, for example, is enclosed in orderto bring the camera into a favorable ergonomic position for theobserver. Further, the additional beam-deflecting elements result indifferent heights of the connection pieces 5 and 6 so that the favorableergonomic arrangement is further improved. Also, the straight-linereflection generates a right-way-round, noninverted image for the camerathat is to be attached. The use of the camera adapter in an ophthalmicmicroscope is shown in FIG. 3.

The technical solution provides a camera adapter for connecting digitalcameras, preferably having a monitor at the back of the housing, to amicroscope, particularly an ophthalmic microscope. By using intermediaterings, the camera adapter is suitable for different cameras having afilter thread and facilitates exchange of cameras. The camera can alwaysbe positioned in such a way that the observer can view the objectthrough the eyepiece as well as on the camera monitor withoutsubstantially changing his/her sitting position.

The use of a surrounding-field illuminator with a controllable LED has aconstant spectrum at all brightness settings, offers sufficient reservepower for difficult illumination conditions, and generates a very smallcornea reflection. The higher, constant color temperature, e.g., of awhite-light LED, in connection with the slit illumination results inhigh-contrast slit recordings. The surrounding-field illuminator has avery simple construction, a long useful life and reliability and caneasily be connected to the power supply of the microscope.

While the foregoing description and drawings represent the presentinvention, it will be obvious to those skilled in the art that variouschanges may be made therein without departing from the true spirit andscope of the present invention.

REFERENCE NUMBERS

-   1 microscope-   2 image out-coupling element-   3 surrounding-field illuminator-   4 housing-   5 microscope-side connection piece-   6 camera-side connection piece-   7 tube optics-   8 eyepiece optics-   9 filter thread-   10 securing device-   11 intermediate rings-   12 dimmer-   13 prism-   14 mirror

1. A camera adapter for optical devices, such as microscopes, having anadditional image out-coupling element for photographic documentation ofimages; said camera adapter to be arranged between the imageout-coupling element and a camera and comprising: a housing with twoconnection pieces, a microscope-side connection piece and a camera-sideconnection piece; said microscope-side connection piece having aquick-change device; said camera-side connection piece having a filterthread and eyepiece optics; and wherein the microscope-side connectionpiece has tube optics.
 2. The camera adapter according to claim 1,wherein the camera-side connection piece is rotatable and has a securingdevice, wherein its filter thread is an M37 thread, and wherein thisfilter thread can be adapted to different thread diameters byintermediate rings.
 3. The camera adapter according to claim 1, whereina right-angle prism and a deflecting mirror are provided as additionalbeam-deflecting elements.
 4. A camera adapter according to claim 1,wherein a surrounding-field illuminator is provided in addition, whereinthis surrounding-field illuminator has a light-emitting diode, andwherein the light-emitting diode emits white light, can be controlledwith respect to brightness and powered by the power supply of themicroscope.